I find that this problem is usually one of the viewer seeing an object of 'known' size.
That is,  if you build a car and place it in a neutral scene you can guess what size the car is supposed to be. BUT, add a human character that is only 2inches tall next to the car and suddenly you have a giant car.

To solve your problem, Uncle, you should maybe zoom in until your building fills the frame and add something we would recognise as being of a particular size....perhaps a tree, a person, or even a car!

Pakled and I discussed this sometime ago, when we were having problems emphisising just how big certain spaceships were when we had nothing to compare them to.  The problem was solved in various ways, one of which was to add very small windows and lights and another, by adding a spaceship of which the size was obvious.

I have noticed however, that you do in fact have trees in your scene. The trick here might be to change the pov until we can see that the trees are between us and the building..........

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All the Woes of a World by Jonathan Icknield aka The Bryster

And in my final hours - I would cling rather to the tattooed hand of kindness - than the unblemished hand of hate...